Duck decoy



FIG. 1 is a perspective view of a design for a duck decoy;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a left side elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a right side elevation view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The support structure shown in broken lines in FIG. 1 is for illustrative purposes only and forms no part of the claimed design. 

I claim the ornamental design for a duck decoy, as shown and described. 